<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="../js/jquery-1.11.3.js"></script>
</head>
<body>
<select multiple size="10">
    <option>请选择</option>
    <option>汉</option>
    <option>蒙古</option>
    <option>回</option>
</select>
<script>
//$('select').val('汉')
$('select').val(['汉','回'])



</script>
</body>
</html>